1. Technical Field
This disclosure relates generally to a reactor which is made up of a core made of a mixture of magnetic powder and resin and a coil wound in the core and a production method thereof.
2. Background Art
FIG. 23 illustrates a reactor 9 for use in an inverter for automotive vehicles. The reactor 9 includes a core 93 made of a mixture of magnetic powder and insulating resin and a coil 92 installed in the core 93. For example, Japanese Patent First Publication Nos. 2010-212632 and 2010-118574 disclose such a type of reactor.
The production of the reactor 9 is, as illustrated in FIG. 24, achieved by putting resin material and magnetic powder in a casing 94 and kneading them so that the magnetic power may be dispersed in the resin material to make a magnetic powder/resin mixture 930 (see an arrow P1). Subsequently, the coil 92 is embedded in place within the magnetic powder/resin mixture 930 (see an arrow P2). The magnetic powder/resin mixture 930 is solidified to make the core 93. This forms the reactor 9, as illustrated in FIG. 23, made up of the coil 93 which is embedded in the core 93 made of the magnetic powder/resin mixture 930 within the casing 94.
The production of the reactor 9 requires, as described above, kneading of the magnetic powder/resin mixture 930 using a stirring blade 95. After the magnetic powder/resin mixture 930 is kneaded, the magnetic powder/resin mixture 930 will be partly adhered to the stirring blade 95 in the form of layers of reactor material 931. It is, thus, necessary to remove the reactor material 931 from the stirring blade 931. Such removal requires solvent, the washing bath 992, and the drying box 993 as well as consumption of the operator's time.
Specifically, after the magnetic powder/resin mixture 930 is kneaded, the stirring blade 95 is, as indicate by the arrow Q1, detached from the stirring motor 991 and then put, as indicated by the arrow Q2, in the washing bath 992. The reactor material 931 is removed from the stirring blade 95 using solvent within the washing bath 992. Subsequently, the stirring blade 95 is, as indicated by the arrow Q3, put in the drying box 993 and then dried to remove the solvent therefrom. The stirring blade 95 is, as indicated by the arrow Q4, taken out of the drying box 993 and then used, as indicated by the arrow Q5, in kneading the magnetic powder/resin mixture 930 in the next production process. A sequence of the operations, as indicated by the arrows Q1 to Q5, are performed cyclically to knead the magnetic powder/resin mixture 930 for mass-producing the reactor 9.
The removal of the reactor material 931 from the stirring blade 95, as just described, consumes much of the operator's time and effort, and requires the use of solvent, the washing bath 992, and the drying box 993, thus resulting in an increase in production cost of the reactor 9.
After removed from the stirring blade 95, the reactor material 931 is usually discarded, thus resulting in a decrease in yield of the reactor 9.
If the solvent remains accumulated on the surface of the stirring blade 95, it may adversely affect the kneading of the magnetic powder/resin mixture 930 in the following production process, which results in degradation of the performance of the core 93. Additionally, a variation in amount of the reactor material 931 adhered to the stirring blade 95 will result in a variation in volume of the core 93, that is, a unit-to-unit variation in size of the reactor 9, which usually leads to a decrease in reliability in operation of the reactor 9.